Roughly 40 school districts in Ohio allow teachers to pack concealed guns in the classroom, and more and more of them are getting trained on how to stop an "active shooter."

"Safety of our kids should not be a controversial issue. This is not about guns," Jim Irvine, of FASTERsaveslives.org and the Buckeye Firearms Foundation, told Fox News.

"For nearly 60 years, not one student has died from a fire. That is due to a redundant, overlapping approach to safety. We should be copying that same method for incidents of violence in our schools. You need something that is effective. Show us another method and we would invest in it."

At the Buckeye Firearms Foundation, teachers train alongside other people seeking a concealed-carry permit, learning how to subdue a threat while students flee a classroom. Paramedic training is also taught, so that teachers can treat any wounded students or staff.

"The single most important factor in active killer death toll is time. The longer killers have their way in so-called 'no-guns' zones, the more people die. The sooner they are stopped, the fewer people die. It is really that simple," said Chad Baus, also with the Buckeye Firearms Foundation.

Superintendent John Scheu, of a 3,500-student school district in Sidney, Ohio, said his district adopted a new policy allowing concealed-carry in the wake of the attack in Newtown, Connecticut, where a gunman killed 20 young children and six staff at Sandy Hook Elementary.

"It made us as a school district look at the system we had in place to keep our children safe," said Scheu. "We quickly learned that we didn’t have anything in place. We decided to be pro-active."

In upstate Ohio, some teachers have sought to train at John Benner’s Tactical Defense Institute

"We've believed in this for a long time, but never thought we'd be able to pull it off until Sandy Hook. And then everything changed. Now people realize if you don't have somebody in the school that's armed willing and capable you're gonna lose a lot of people," Benner, a former SWAT commander, told WKRC-TV.